Still, the shares have declined 6% since their high in March, as investors have become nervous about the pace of its international expansion and the progress of rivals such as Sainsbury's.

And Tesco - along with other supermarkets - is facing yet another inquiry into its market power. Its chief executive Terry Leahy has insisted it is not "dominant" despite its growing share of the UK market.

Record profits

Tesco posted a big rise in profits and sales in April, with both UK and international sales growing rapidly.

Total sales rose 13% to £41.8bn, while like-for-like sales - which exclude new store openings - at its UK outlets rose 7.5%.